One of my on-going projects is research into  the Anglo-Saxon era in the UK -- 450AD to 1066AD.  I "know that the A-S used slings, and knew that sling pouches had been found in Jorvik (Viking era York), but hadn't seen a written reference until this:

St. Aldhelm (639-709) collected riddles (one of the favorite entertainments of Anglo-Saxon time) in a book of 100 riddles called the Aenigmata, in Latin. The answers tend to be objects that would be familiar to the Anglo-Saxons, so the inclusion of the sling is particularly interesting:

" The flax plant, blooming fair in level fields
    And a bull's hide, gave me my origin .
    Two bonds of twisted cord restrain my leap
    And thus long since I slaughtered with a weight
    A mighty tyrant, when the marshaled host
    Was bent on cruel war; for I prefer
     To win my battles with a smooth round stone
    Rather than with hard iron headed pikes.
     Three fingers whirl me high about the head;
      I turn, and dart away into thin air. "

What am I?   A sling.

Interesting that it describes what must have been the common construction materials -- Flax (raw linen) and bullhide.

I don't read Latin, but I have just found a reputable English translation and have downloaded by not read it yet.

Here's the Latin and English translation from a 1925 by Translation of the Aenigmata by James Hall Pitman:

LXXIV.  Fundibalum
Glauca seges lini vernans ex aequore campi
Et tergus mihi tradebant primordia fati.
Bina mihi constant torto retinacula filo,
Ex quibus immensum trucidabam mole tirannum,
Cum cuperent olim gentis saevire falanges.
Plus amo cum tereti bellum decernere saxo
Quam duris pugnans ferrata cuspide contis.
Tres digiti totum versant super ardua corpus;
Erro caput circa tenues et tendor in auras.



74.  Sling
The flax-plant, blooming fair in level fields,
And a bull’s hide, gave me my origin.
Two bonds of twisted cord restrain my leap,
And thus long since I slaughtered with a weight
A mighty tyrant, when the marshaled host
Was bent on cruel war; for I prefer
To win my battles with a smooth, round stone
Rather than with hard iron-headed pikes.
Three fingers whirl me high about the head;
I turn, and dart away into thin air.

Even if this is "just" an allegory; and Aldhelm apparently loved his allegories, it still gives slingers a look at what the Anglo-Saxons, "vikings" and native Britons were doing with slings before 1066 -- twisted flax cords, leather pouch, three-finger grip, whirling high above the head...  And the attitude of "rather be a slinger than s spearman"!

yeah, basic grip is 2 fingers and a thumb.
Makes sense

That is pretty cool

Well, if you're going to be pedantic or uber-realistic, then  "bullhide" was just a synonym for all leather, and probably made a better rhyme in Latin than in modern English.  Also, thick hides can be split to make thinner hides, so I don't see any issue there.

"Three fingers" tell us they weren't using the old "full fist" hold.  I don't use more than three fingers, certainly; although some cultures did.

Alternative translation from https://books.google.ch/books?id=37rwCgAAQBAJ&pg=PA44&lpg=PA44&dq=Erro+caput+cir
ca+tenues&source=bl&ots=ILltqlaEWY&sig=ACfU3U3fVpbNyOehDsv9zLwr6jZCsdt50w&hl=de&
sa=X&ved=2ahUKEwidp6ujpdr2AhWD6aQKHZUIDroQ6AF6BAgREAM#v=onepage&q&f=false
Saint Aldhelm's 'Riddles', A.M. Juster, University of Toronto Press, 2015

My start began from flat and blooming fields,
Some leather and the light-blue flaxen yields.
They make me with twin bands of twisted string
With which I slew with stone a brutish king
Back when a crowd of brawlers longed for gore.
I pick a polished stone that ends a war
Instead of hard-tipped iron spears to fight.
Three fingers fling my body to great height;
I loop a head and in thin air I soar.

From what I can tell with the latin I still remember, both translations take considerable "poetic" freedom, to the extent that the meaning is changed.

In this case I'd rather have the sense than trying to match the rhyme 

Good topic, StaffSlinger.
With this text, we know more about the slings of York.

Does anyone know more about the excavations ? The leather used ? The cord found with the third sling ?